Detection of metastable excited molecules N2(A3Σu+) in an atmospheric pressure nitrogen discharge by Raman scattering

Abstract

AbstractRaman scattering from metastable excited nitrogen molecules N2(A3Σu+) created by an impulse discharge in nitrogen at atmospheric pressure was detected. A pulsed Nd:YAG laser at a wavelength of 266 nm was used as the light source, and Raman scattering from N2(A3Σu+) at a wavelength of 277 nm was detected using an interference filter and photomultiplier tube. The filter had sufficient rejection of Rayleigh scattering of laser light at a wavelength of 266 nm and of Raman scattering from ground‐state nitrogen molecules N2(X1Σg+) at a wavelength of 284 nm. The temporal variation of the signal intensity of Raman scattering from N2(A3Σu+) was measured by transmitting the laser light at different time delays relative to sparkover. The results showed that the signal intensity decayed with a time constant of about 200µs. © 2010 Wiley Periodicals, Inc. Electron Comm Jpn, 93(6): 34–40, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10205